Stabilization of three-dimensional matter-waves solitons in an optical latticeM. Trippenbach1, M. Matuszewski1 and B. A. Malomed2
1 Physics Department, Warsaw University - Hoza 69, PL-00-681 Warsaw, Poland
2 Department of Interdisciplinary Sciences, School of Electrical Engineering Faculty of Engineering, Tel Aviv University - Tel Aviv 69978, Israel
received 7 October 2004; accepted in final form 9 February 2005
published online 9 March 2005
We propose an experimentally relevant scheme to create stable solitons in a three-dimensional Bose-Einstein condensate confined by a one-dimensional optical lattice (OL), using spatially uniform temporal modulation of the scattering length (through ac magnetic field tuned close to the Feshbach resonance). Another physical implication of the model is a possibility to create stable 3D "light bullets" in an optical medium with a longitudinal alternating self-focusing/defocusing structure, and periodic modulation of the refractive index in a transverse direction. We develop a variational approximation to identify a stability region in the parametric space, and verify the existence of stable breathing solitons in direct simulations. Both methods reveal that stable solitons may be supported if the average value of the nonlinear coefficient (whose sign corresponds to attraction between atoms) and the OLs strength exceed well-defined minimum values. A moderately strong OL supports multi-peaked solitons, with essential interaction between the peaks.
03.75.-b - Matter waves.
03.75.Lm - Tunneling, Josephson effect, Bose-Einstein condensates in periodic potentials, solitons, vortices and topological excitations.
05.45.Yv - Solitons.
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